30 lines
599 B
C
30 lines
599 B
C
/*
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* Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
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*
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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#include <stdint.h>
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#include <lib/utils.h>
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#include <lib/utils_def.h>
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#include <drivers/rpi3/rng/rpi3_rng.h>
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/* Get 128 bits of entropy and fuse the values together to form the canary. */
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#define TRNG_NBYTES 16U
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u_register_t plat_get_stack_protector_canary(void)
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{
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size_t i;
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u_register_t buf[TRNG_NBYTES / sizeof(u_register_t)];
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u_register_t ret = 0U;
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rpi3_rng_read(buf, sizeof(buf));
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for (i = 0U; i < ARRAY_SIZE(buf); i++)
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ret ^= buf[i];
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return ret;
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}
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